In the prior art, the voltage-controlled oscillator (VCO) has undesirable gain coefficients with respect to power supply variations which change the frequency of oscillation of the VCO. When the VCO in a phase-locked loop (PLL) unilaterally changes its frequency, the PLL feedback loop must correct this aberration. Since the unity gain frequency of the PLL feedback is low compared to the oscillating frequency of the VCO, many cycles elapse before the error is eliminated. It is a standard practice in PLL design to utilize a VCO which is as insensitive as possible to variations in the power supply voltage; however, there is a continuing need for improved VCO's with immunity to power supply voltage variations.